1. Field of the Invention
The present invention relates generally to devices for collecting and transporting liquid samples. More particularly, the subject devices are used for collecting and transporting samples of liquids for analytical testing.
2. Description of the Prior Art
The sampling of fluids for diagnostic or evidentiary purposes is very common. Such fluids, which include urine, blood, water, milk etc., are collected in a specimen container and transported to a laboratory where they are analyzed to determine the presence of infections or contaminants such as drugs, alcohol etc. Under such circumstances, the collected sample must be maintained uncontaminated until the various testing procedures have been concluded. Containers for this purpose are common and usually comprise a plastic container having a secure lid.
The first step in analyzing the sample is normally the extraction of an aliquot of the collected fluid. Since the collected samples may pose a biohazard risk, great care must be taken to ensure that the liquid sample is not spilled during the handling of the container or the extraction of the desired aliquot. Further, in order to protect the accuracy of the analytical results, it must be ensured that no contaminants mix with the sample.
It is now preferred for the analytical process to be automated which involves the use of robotics to handle the specimen container and to conduct the various chemical and biochemical tests on the liquid sample. To conduct the desired tests, an aliquot of the sample is extracted from the vial and passed into a testing chamber (a test tube for example). As mentioned above, it must be ensured that the fluid sample is not spilled onto any part of the apparatus and that, during the extraction of such aliquot, another sample or other material does not contaminate the sample. Thus, specimen containers must be designed to be suitable for use in both manual and automated analytical processes.
Another issue arises in cases where biological samples are collected for evidentiary purposes. In such situations, the established protocols call for two samples of fluid to be collected and maintained in separate containers. One of such samples proceeds through the analytical process while the second is maintained uncontaminated for later reference if needed. In these cases it is important to maintain a proper chain of custody of the two samples so as to prevent tampering. Normally, the sample is collected in a collection cup and separated into transport containers, which are attached together, usually by rubber bands, until they reach the laboratory. Although the containers are labeled, they can easily be misplaced rendering further verification of the tests impossible and corrupting the chain of custody.
To address the safe transfer of the desired aliquot of the sample, various modifications to the container lid have been proposed. An example of such modification is described in U.S. Pat. No. 5,395,590 wherein Swaniger et al. teach a valved plastic lid for a specimen container. The '590 lid includes a valved opening in the center which comprises a number of slits, which, due to the elasticity of the plastic material, are normally closed. However, upon applying an inward force to the lid, the slits open and allow the contained fluid to pass through. In extracting fluid from a container having such lid, the opening of a second container, such as a test tube, is placed over the opening in the lid and the two containers are inverted. The first container is then forced downward thereby causing the slits in the lid to open and allowing fluid to enter the second container. However, the lid taught in the '590 patent has certain disadvantages. For example, the slits in the lid can be forced open prior to the testing process by applying pressure thereto and thereby allowing contaminants to enter the container. Similarly, the collected sample may also be inadvertently spilled thereby requiring a separate closure until the sample is extracted. Further, the manufacture of such a complicated structure adds to the cost of such a lid.
In U.S. Pat. No. 4,917,867, Jensen et al. teach an apparatus for the collection of dual biological samples. This reference describes a kit comprising a container containing two sample vials and other items to obtain the desired samples. After collecting the samples, the vials are placed back into the main container. Although accounting for the chain of custody during transfer, the apparatus of this reference requires the separation of the sample vials prior to the analysis process thereby resulting in the possibility of one of them being misplaced.
Thus a need exists for a specimen container which overcomes the above-identified deficiencies in the known devices.